Digital color balance and SCUBA diving

Archived from groups: rec.photo.digital (More info?)

>Should following a normal "custom" white balance process while at depth
>result in accurate color capture? Any special considerations?

Actually, white-balance adjustments are designed specifically not to
give you accurate color capture, but rather to make the photo look
most like what the eye sees.

The eye (along with the mind) automatically converts most off-white
ambient light to white, so even in a large range of settings, white
looks white.

Film and digital sensors don't do this conversion automatically, so
they have to be set according to the lighting. Normally, this is a
good thing, but in caes of extreme lighting (sunsets, under water) you
don't want the lighting to look the same as it would it ordinary
daylight.


I would recommend shooting in RAW mode (if you can) and adjsuting
things later. Or if you cannot, shoow in a variety of WB settings.

-Joel

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Archived from groups: rec.photo.digital (More info?)

My recent experience in Hawaii:
Even in depths of just 10meters red light is fairly well filtered out by the
water as far as digital cameras are concerned. Using flash underwater is
often a problem as waterborne particles reflect the light back at the
camera. Post exposure color correction helps but the color effect is rather
unrealistic but better than nothing.

Archived from groups: rec.photo.digital (More info?)

On Thu, 24 Mar 2005 02:13:31 -0000,
nobody@imaginary-host.danbirchall.com (Dan Birchall) wrote:

>apquilts@pacbell.net (bmoag) wrote:
>> My recent experience in Hawaii:
>> Even in depths of just 10meters red light is fairly well filtered out
>> by the water as far as digital cameras are concerned.
>
>Yep. Actually, I'd say that's true at even shallower depths - I do a
>lot of skindiving with a digital, and there's a lot of blue/green.
>
There actually isn't enough red light to get a colour balance. Shoot
RAW.

>> Using flash underwater is often a problem as waterborne particles
>> reflect the light back at the camera.
>
>Yep. "Backscatter." How much of a problem it is varies depending on
>recent weather patterns (rain will cause runoff), time of day (morning
>is clearer, before everyone gets to the beach) and how still the water
>is, among other things.

Move the strobe a long way from the camera, and in extreme cases, well
behind the camera. Shooting mantas with a 10.5mm lens I have the
strobe about 18" behind and about 4' away from the lens centre.
Further is better!!

Pete S.

Archived from groups: rec.photo.digital (More info?)

fake@ (Pete S.) wrote:
> nobody@imaginary-host.danbirchall.com (Dan Birchall) wrote:
> >apquilts@pacbell.net (bmoag) wrote:
> >> Using flash underwater is often a problem as waterborne particles
> >> reflect the light back at the camera.
> >
> >Yep. "Backscatter." How much of a problem it is varies depending on
> >recent weather patterns (rain will cause runoff), time of day (morning
> >is clearer, before everyone gets to the beach) and how still the water
> >is, among other things.
>
> Move the strobe a long way from the camera, and in extreme cases, well
> behind the camera. Shooting mantas with a 10.5mm lens I have the
> strobe about 18" behind and about 4' away from the lens centre.
> Further is better!!

Agreed! Backscatter is worst when the flash is near the axis of
the lens. When I'm skindiving with a compact camera, I try to avoid
using the flash at all for this reason - the flash is an inch or two
from the lens axis.

Someday I'll be able to afford a nice housing with the external strobes
and all that good stuff.

--
Dan Birchall, Hilo HI - http://hilom.multiply.com/ - images, words, technology